Looks like a big comp with lots of (animated) layers, over which they move a camera. Just add a camera in your After Effects and toy around with that, no real big stunts are pulled in this movie.
Oh, and be sure to ease-in and ease-out the movement keyframes, that really smoothes things out (or just select all keyframes and press F9, it does wonders most of the time). Plus, you need to turn on your motion blur on all layers. It really increases the feel of smooth movement